1. Field of the Invention
The present invention relates to am information processing system, an information processing apparatus, and a control method for the information processing system.
2. Description of the Related Art
Attention has been paid to disaster recovery in an information processing system. With one of known technologies for realizing disaster recovery, copies of data in a storage apparatus installed at a primary site are managed also by a storage apparatus installed at a remote site. When the primary site is hit by a disaster, a computer at the remote site inherits processes executed by a computer at the primary site, i.e., performs so-called fail-over, to continue the processes by using data copied to the storage apparatus at the remote site.
In the information processing system, unexpected failures of data may happen such as miss-operation of data and contamination by viruses. In order to allow data at past time points to be recovered, either the primary site or the remote site periodically backs up copies of data.
The specification of U.S. Pat. No. 5,155,845 discloses a data storage system which stores redundant data copies in disk drives.
If failures occur at the backup executing site, the processes at this site are inherited to another site. However, backup data does not exist until the data is backed up. In this case, if disasters or other failures occur at the fail-over destination site, there is a fear that data cannot be recovered.